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Hidden sacrifice

AN ALARMING number of mice are being slaughtered because they don’t take up
the DNA that genetic engineers are trying to insert into them. Bioethicists
voiced concern over the waste of life, and its effects on the emotional
wellbeing of the technicians who have to dispatch the animals, at a meeting in
London last month on the effects of biotechnology on animal welfare.

Most biologists agree that transgenic technology has the potential to bring
huge advances in fundamental research and medicine. By altering mouse genes,
they can unlock the genetic secrets of development, or create animal models in
which to study devastating human diseases.

Laboratory animals have always had to be be humanely killed, once they can no
longer be used in experiments or for breeding. But genetic engineering makes the
problem worse. When researchers inject new genes into animal embryos, only
between 1 and 10 per cent of them will incorporate the gene.

And while fewer animals in general are being bred for scientific experiments,
transgenic mice are a growth area. Their use in Britain has increased sevenfold
during the 1990s (see Figure).
The Home Office, which regulates animal
experiments in Britain, says that the “waste” animals should be included in the
statistics for transgenic procedures. But some observers believe many are being left out.

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“It’s very difficult to work out the exact number killed surplus to
requirements,” says David Morton, head of the centre for biomedical ethics at
the University of Birmingham. “I think a lot of people may cull them and not
count them.”

Richard McGowan, a spokesman for the Fund for the Replacement of Animals in
Medical Experiments in Nottingham, wants scientists to look for ways of reducing
the wastage. One option would be to use transgenic “failures” to provide tissue
for research, instead of the hundreds of thousands of animals that are
specifically bred for this purpose each year(This Week, 25 October 1997, p 25).

But McGowan concedes that matching supply to demand may be difficult, as the
scientists involved may be in different labs, and require the animals at
different times. So until transgenic techniques improve so that genes can be
more reliably incorporated into the genomes of mouse embryos, much of the
wastage is likely to continue.

In the meantime, Morton believes that scientists should consider carefully
the effects of the boom in transgenic animals on the technicians who have to
kill the surplus animals. “They are often told to mop up afterwards,” he
says.

One senior animal technician at a leading British university says that she
has noticed an increase in the numbers sacrificed as genetic engineering has
expanded: “My remit is to ensure we don’t overbreed animals, but with
transgenics, you can’t do anything about the surplus.”

She, for one, is disturbed by being asked to kill so many animals. “I go away
feeling physically and emotionally exhausted, and I think it’s important for
people to understand how we feel.” She believes that an anonymous questionnaire
would reveal the extent of emotional problems among technicians.

John Gregory, chairman of the Institute of Animal Technologies, which
represents Britain’s animal technicians, says his organisation is open to the
idea of conducting a survey, and would help to arrange counselling if necessary.